MCKESSON CORP

To the Stockholders and the Board of Directors of McKesson Corporation

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheets of McKesson Corporation and subsidiaries (the "Company") as of March 31, 2025, and 2024, the related consolidated statements of operations, comprehensive income, stockholders’ equity (deficit), and cash flows, for each of the three years in the period ended March 31, 2025, and the related notes and the schedule listed in the Index at Item 15 (collectively referred to as the "financial statements"). We also have audited the Company’s internal control over financial reporting as of March 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013)issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of the Company as of March 31, 2025, and 2024, and the results of its operations and its cash flows for each of the three years in the period ended March 31, 2025, in conformity with accounting principles generally accepted in the United States of America. Also, in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of March 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by COSO.

Basis for Opinions

The Company’s management is responsible for these financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on these financial statements and an opinion on the Company’s internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects.

Our audits of the financial statements included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures to respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Uncertain Tax Position, Opioid-Related Claims - refer to Note 1 and Note 6 to the financial statements

Critical Audit Matter Description

The Company has recorded charges and related tax benefit for opioid-related claims. In order to account for the uncertainty associated with the ultimate realization of the income tax benefit related to opioid-related claims, the Company recorded an uncertain tax position reserve. Tax benefits from uncertain tax positions are recognized when, based upon the technical tax merits, it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes. The net amount of income tax benefit recognized by management is measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized. The Company uses significant judgment in evaluating the technical tax merits of income tax benefits that qualify for recognition, including the determination of the amount that is more likely than not of being realized for U.S. federal and state income tax purposes.

We identified the Company’s uncertain tax position related to liabilities arising from opioid-related claims as a critical audit matter because of the challenges in auditing management’s estimate of the amount of income tax benefit that qualifies for recognition. Specifically, there is significant judgment associated with the assessment of the technical tax merits, including the related interpretation of applicable tax laws and regulations. Auditing the uncertain tax position related to liabilities arising from opioid-related claims required a high degree of auditor judgment and an increased extent of effort, including the need to involve our tax specialists.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to the Company’s uncertain tax position associated with liabilities arising from opioid-related claims included the following, among others:

•We tested the effectiveness of the Company’s internal control related to management’s assessment of the technical merits of its tax position and the amount of benefit more likely than not to be realized related to liabilities arising from opioid-related claims.

•With the assistance of our income tax specialists, we evaluated the facts, evidence and the Company’s related income tax analysis for the uncertain tax position reserve associated with liabilities arising from opioid-related claims.

•We held inquiries with the Company’s internal and external income tax specialists related to the uncertain tax position for liabilities arising from opioid-related claims.

•We evaluated any events after March 31, 2025, that might affect management’s accounting treatment and related applicable disclosures.

•We obtained written representations from executives and internal legal counsel of the Company.

•We obtained and reviewed terms related to the Company’s settlements of opioid-related claims and evaluated them against the deductibility criteria set forth by relevant tax laws and regulations.

•We evaluated the Company’s related disclosures for consistency with our testing and also searched for contradictory evidence by reading disclosures from peer companies, who are also party to opioid-related litigation.

/s/ Deloitte & Touche LLP

Dallas, Texas

May 8, 2025

We have served as the Company's auditor since 1968.